• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Find which factor has the greatest effect on deciding the planform of the River Arrow in Herefordshire, by studying slope angle and discharge amongst other varying elements.

Extracts from this document...


Kristina Gilbert Geography A-level Coursework River Study Introduction Study Area Method Pg 3 Pg 5 Pg 6 Introduction The overall aim of this investigation is to find which factor has the greatest effect on deciding the planform of the River Arrow in Herefordshire, by studying slope angle and discharge amongst other varying elements. Rivers are a primary feature of the world's surface area. Hundreds of networks of river channels together drain almost 70 percent of the earth's land surface and their characteristics differ from location to location and also at the same location over a time period, known as a river regime. In order to fully investigate the main question of this investigation, a number of subsidiary questions have been devised. Each of these in turn will help to provide answers in investigating the reasons for variation in planform. * 1. How does the planform vary along the river? * 2. Is the slope angle steeper on meandering bends than on straight sections? * 3. How do discharge and velocity compare on different planforms? * 4. Does Channel roughness effect planform? * 5. Does Landuse on the banks influence the planform shape? Turbulent flow is the major flow type in most natural river channels. It is this which justifies their efficiency in both the eroding and transporting of materials and sediment. The velocity of a river is affected by three main things, channel roughness, channel shape and gradient. ...read more.


Streams with a low sinuosity, which are comparatively straight, are associated with areas of a gentle gradient. "Their low sinuosity is a reflection of their aimless plan where sluggish downstream water velocity has not imposed a regular meander pattern on the system." (Challenge of the Natural Environment, Knapp, Ross and McCrae) Study Area: The River Arrow, Herefordshire The river Arrow, is a tributary of the river Lugg which in turn is a tributary of Herefordshire's largest river, the Wye. The Arrow is a relatively small river and so this meant that it would be safe to take readings from. I chose to focus on a small area of the Arrow near to Kington, one of Herefordshire's market towns. It is situated between the river Arrow and its tributary the Gilwern Brook. The landuse around the river in the area around the Kington area is very similar, most of it being fields for the grazing o livestock, although there are small areas of woodland either side of the town. The town centre is set away from the river's banks and so there has been very little development along the river barring a few houses and a small campsite. Method: Sampling Strategy: When deciding how to collect the field data required to carry out this investigation, it is important that the process is both practical and efficient, and therefore needs to be planned well. ...read more.


Velocity (in m/sec) In finding velocity a flow meter should be used, placing approximately two thirds of the depth beneath the waters surface for one minute and recording the result, which will show you how many revolutions the propeller has turned. By doing this three times across the width of the river at regular intervals you will get a reading across the whole of the river. These count figures can then be added together and divided by three to get an average. This is then used alongside a mathematical equation which will give the velocity reading: Velocity = (0.144 * count) +5. To obtain the answer in m/s as apposed to cm/s you would then divide your answer by 100. Pebble Size (in cm) Pebble size should also be recorded when depth readings are taken, at each given depth, ten regular intervals across the river, a systematic sample the pebble on the river bed should be measured by its B axis. This sampling method is appropriate as it should give fair results, with pebble sizes across the whole width of the river Secondary Data Collection Gradient (in degrees) The gradient will be measured through taking readings from contour lines on a map. By taking the measurement this way an exact reading will be given, providing the sites are marked definitely on the map. It is sometimes not possible to take gradient readings when in the field as the banks can be inaccessible. The use of an OS map subtracts any chance of unsuccessful readings on the day due to physical obstacles. 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Hydrology & Fluvial Geomorphology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Hydrology & Fluvial Geomorphology essays

  1. An investigation into changes in channel parameters down the river Horner

    by shallow areas these are called pools and riffles when I took my readings for depth I took them regardless of weather that particular cross section was a pool or a rifle.

  2. Geography Coursework: Epping Forest

    This is only a slight increase but this may be because the size of the Loughton Brook River is small so I would not expect to see a large change. Also the shape of the three diagrams shows that the left side of the river is deeper than the right side.

  1. Study the downstream changes of Loughton Brook.

    The lateral erosion makes the riverbed steeper during the earlier stages of the river and so the gradient is seen as decreasing. At Site 2 the gradient was 0.21� in my results, and at Site 3 and Site 9 was 0.2� and 0.05� respectively.

  2. Geography investigation - The River Skirfare located in the Littondale region in the Yorkshire ...

    Indeed, it is only a gap of 3.75mm. The cause of this perhaps is the anomaly in the results at Arncliffe, where there is a very large result, 120mm, amongst other results that go no higher than 70mm. This will be further discussed in the next section though.

  1. How does Loughton Brook change as it moves downstream?

    It shows a fairly strong positive correlation. If the discharge increases as we go downstream that means that there is less particles in the water to restrict the flow of water. Therefore this also proves that the efficiency increases as we move down stream.

  2. How Do River Characteristics Vary Downstream?

    Significance Level - Refers to the probability of the correlation being correct and statistically significant. N - Number of observations, in this case, the number of sites. Calculations for the figures on the previous page are shown in Figure 4.2.

  1. Investigating the river Caerfanell

    This method was completed last of all because if I changed the river physically by unconsciously moving the rocks before I had completed the other tasks it would have disturbed the natural flow of water thus affecting the other methods results such as velocity readings and also would have

  2. I am going to study the characteristics of rivers and how they change as ...

    The velocity can increase if the slope is steep and if not the velocity would be less. If the channel depth and width is high, the wetted perimeter would be high in the river. The pebbles on the riverbed would either be rounded or become smaller on stream order 4

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work